Spin Polaron Effective Magnetic Model for La_{0.5}Ca_{0.5}MnO_3

Abstract

The conventional paradigm of charge order for La_{1-x}Ca_xMnO_3 for x=0.5 has been challenged recently by a Zener polaron picture emerging from experiments and theoretical calculations. The effective low energy Hamiltonian for the magnetic degrees of freedom has been found to be a cubic Heisenberg model, with ferromagnetic nearest neighbor and frustrating antiferromagnetic next nearest neighbor interactions in the planes, and antiferromagnetic interaction between planes. With linear spin wave theory and diagonalization of small clusters up to 27 sites we find that the behavior of the model interpolates between the A and CE-type magnetic structures when a frustrating intraplanar interaction is tuned. The values of the interactions calculated by ab initio methods indicate a possible non-bipartite picture of polaron ordering differing from the conventional one.

arXiv comment21 pages and 8 figures (included), Latex

References in corpus (10)

• Exact spectra, spin susceptibilities and order parameter of the quantum Heisenberg antiferromagnet on the triangular lattice
• Novel stripe-type charge ordering in the metallic A-type antiferromagnet Pr{0.5}Sr{0.5}MnO{3}
• Spin wave analysis to the spatially-anisotropic Heisenberg antiferromagnet on triangular lattice
• The Heisenberg antiferromagnet on an anisotropic triangular lattice: linear spin-wave theory
• Ab initio evaluation of local effective interactions in ${\alpha }^{\prime }Na{V}_2{O}_5$
• Exchange coupling in CaMnO${}_3$ and LaMnO${}_3$: configuration interaction and the coupling mechanism
• Ferromagnetic Polarons in La0.5Ca0.5MnO3 and La0.33Ca0.67MnO3
• Phase Competition in Ln0.5a0.5mno3 Perovskites
• Neel probability and spin correlations in some nonmagnetic and nondegenerate states of hexanuclear antiferromagnetic ring Fe6: Application of algebraic combinatorics to finite Heisenberg spin systems
• Magnons in the half-doped manganites

Cited by in corpus (5)

• Zero-temperature magnetic response of small fullerene molecules at the classical and full quantum limit
• Discontinuous quantum and classical magnetic response of the pentakis dodecahedron
• Ground state magnetic response of two coupled dodecahedra
• Influence of the biquadratic exchange interaction in the classical ground state magnetic response of the antiferromagnetic icosahedron
• Thermalization of a Dimerized Antiferromagnetic Spin Chain